During the spin cycle of the washing machine, when water is removed from wet clothes centrifugally by spinning the clothes in a spin basket, it is important that the washing machine lid remains closed to prevent injury to the user. For this reason, the lid is normally connected to an electrical switch which controls a mechanism to stop the motion of the spin basket when the lid is raised.
For reasons of manufacturing convenience and to reduce the possibility of the switch being defeated, it may be desirable to place the lid switch near the lid hinge. At this position, however, there is very little motion of the lid when the lid is opened. As a result, the lid switch must be carefully adjusted during manufacturing to ensure that the spin basket is stopped before the lid is opened too far. This adjustment may be accomplished, for example, by mounting the lid switch to a slide adjustment bracket, which is manually located and tightened into position with one or more screws. This adjustment process increases the cost of manufacturing the washing machine and creates the potential for future misadjustment if the screws become loosened.
One method of providing a rear-mounted lid switch that may accurately operate with small openings of the lid without the need for manual adjustment is through the use of a self-adjusting link positioned between the electrical contacts of the switch and the lid. The self-adjusting link is compressed or otherwise deformed upon the first closing of the lid to precisely fix the relationship between the actuation of the electrical contacts and movement of the lid. Several such self-adjusting links are disclosed in U.S. Pat. Nos. 5,600,976, 5,682,772, 5,691,520 and 5,728,985 assigned to the assignee of the present invention and hereby incorporated by reference.
By providing for automatic adjustment of the switch actuation point, these designs all allow simpler assembly of the laundry machine by eliminating the need for time consuming manual adjustment.